Unitary power module for electric bicycles, bicycle combinations and vehicles

ABSTRACT

A wheeled vehicle comprises a frame having a steerable front wheel having an axle affixed to a front portion of said frame, and a hub rear wheel having an axle affixed to a rear portion of said frame. A unitary power module is used as a propulsion system, which includes a target sprocket and a mounting frame, with the target sprocket comprising a disk shaped assembly having an center opening to allow the unitary member to be placed about the wheel axle. The target sprocket mates to the hub (or axle) of either of the wheels to enable target sprocket to be concentrically attached to the wheel by engagement with the wheel by securing elements. The mounting frame may be aligned with and rotatably attached to the target sprocket to allow for aligned rotation of the target sprocket about the wheel axle. The mounting frame may be attached to the unitary member by a bearing or the like and has an opening to receive an electric motor having a pinion sprocket to enable the pinion sprocket to engage the target sprocket to rotate the rear wheel upon application by the rider of propulsion controls. A free wheel clutch may be provided on the unitary power module or target sprocket to allow the wheel to rotate faster than the motor without motor drag.

This application is a Continuation of application Ser. No. 09/302,301,filed Apr. 30, 1999, now U.S. Pat. No. 6,269,898, which is aContinuation-In-Part of application Ser. No. 09/028,119, filed Feb. 23,1998, now U.S. Pat. No. 5,937,964, which claims the benefit ofProvisional Application No. 60/040,865, filed Mar. 18, 1997, nowexpired.

BACKGROUND OF THE INVENTION

The present invention relates to an electric motor bicycle, and moreparticularly to a unitary self-contained direct drive power module (or“unitary power module”) for electric bicycles or other vehicles. Theinvention also includes a kit for converting a standard bicycle into anelectric bicycle by use of the unitary power module.

By way of background information, and turning now to the drawings, FIG.19(a) illustrates a standard bicycle 100 (“or bicycle”), which is a twowheeled vehicle comprised typically of a front steering wheel 102 and arear wheel 104, which may be attached to the frame by quick-disconnectunits 105. The standard bicycle 100 includes a frame assembly 106 havinga head tube 108 which journals a front fork 110 for steering via handlebars 109 by a rider of the bicycle 100. As illustrated in FIG. 19(b),the rear wheel 104 is journalled at the rear end of the frame 106 by apair of rear stays (or “dropouts”) 112. A seat tube 111 is carried bythe frame 106 adjacent the rear wheel 104 and a seat post 113 upon whicha saddle type seat 115 is positioned thereon to accommodate a rider.

In the standard bicycle 100, a horizontally oriented journal (or crankjournal) 117 is positioned beneath the seat tube 111 which supports arider “propelled” drive mechanism 120. The drive mechanism 120 generallycomprises a crank 123 journalled in the crank journal 117, whichincludes a chain sprocket 129 having a plurality of teeth, together withthe crank 123 positioned therein with along with pedals 125 rotatablyjournalled at each end 127 of the crank 123.

Each wheel typically consists of a tire 114 mounted on a rigid rim 116,an axle 118, a hub mechanism (or “hub”) 122 and spokes 124 connectingthe rigid rim 116 to the hub 122 to form an axle/hub assembly 121. Thehub 122 surrounds the axle 118 and is free to rotate about the axle 118through a bearing assembly 126 (not shown). The tire/rim assembly 128 isattached to the hub 122 through an assembly of the spokes 124 which areassembled in a woven pattern 130 to form a wheel/hub assembly 140. Thiswoven pattern 130 of spokes has relatively few variations with a largequantity of existing bicycle wheels being common in using the same orsimilar thirty-six or thirty-four spoke weave pattern 130. A target“chain” sprocket 150 is mounted about the rear wheel 104, and isconnected to the crank sprocket 129 by a chain 152 whereby applicationof power by the rider on the pedals 125 propels the bicycle 100. Aderailleur 154 is often substituted for the single target sprocket 150(or target sprocket), and may have a plurality of sprockets 156, 158,160, 162, 164 and 166 (illustrated in FIG. 9) to provide variablegearing for rider comfort when either starting or climbing hills or forrider efficiency.

One of the features of a bicycle, is the ability of the wheel to beremoved for servicing, such as repairing a flat. As described above, thetypical bicycle wheel is constructed of a tire/rim assembly connected tothe hub through a series of woven spokes. The hub rides on the axle ofthe wheel using a bearing assembly. The axle/hub assembly typically hasrather loose manufacturing tolerances and as such provides a poorreference frame for the propulsion elements of prior systems. Thisoccurs because bicycles are typically high rate, low-cost, manufacturedconsumer products, whereby the tolerances of components are not as highas a high quality mechanism. The majority of bicycles sold in the worldand in use are in the lower or looser tolerance ranges. Also, when thewheel (or tire) is repaired and then replaced in the dropouts of theframe, the axle can become slightly cocked with respect to the frame. Assuch, tolerances for the mounting slots of the wheel axle allow for awide latitude of assembly. The loose manufacturing tolerances of theaxle and axle/hub bearings is typical of such low-cost mechanisms. Theselarge tolerances of wheel and bicycle frame components present asignificant problem in the design of reliable direct drive propulsionsystems where various components of the system are mounted on differentparts of the bicycle (e.g., on the frame, on the axle, etc.)

If the various components of the propulsion system are mounted onbicycle components, which have loose tolerances in reference to eachother, then the propulsion system suffers (or will suffer) from thesesame poor alignment tolerances with rough usage. In order to avoidexcessive wear, reduced efficiency, and reduced performance as a resultof such loose tolerances, an effective propulsion system should ideallyutilize a design which is independent of such loose tolerances in theaxle/hub assembly of the bicycle as well as the changing tolerancesrelative to the frame. It is this design concept which forms thisinvention.

In the past, electric propulsion systems for bicycles have beenimplemented through a variety of methods which utilized electric motorpower to either supplement or replace the above rider drive mechanism inpropelling the bicycle. For example, these methods include frictionroller drives, belt drives, gear drives, and chain drives. For example,friction drives typically involve the application of an electric motoror “the drive source” to a wheel or “the target mechanism” through aroller mechanism. The roller may be directly attached to the drivesource or through a clutch mechanism. The roller transfers the drivesource energy through the contact of the roller on the target wheelthrough friction between their respective surfaces. This type of drivesystem suffers from mechanical losses associated with slippage betweenthe roller mechanism and the target wheel as a result of reducedfriction and from the energy required to compress the rubber tire.Performance in moisture, rain, snow and mud is marginal at best.

By way of further example, electric bicycles having direct drivesystems, such as belt, gear and chain drives typically provide higherenergy coupling efficiencies than the roller friction drive systems.These systems however require a high degree of mechanical integrity inthe geometry of drive components. For instance, there needs to besufficient tension in the belt and chain of the belt and chain drivesystems and the proper alignment or meshing of the gears in the geardrive system. Proper and exact mechanical alignment must be maintainedrigidly with shock and many tire and wheel repairs in order to extendthe life of the unit.

There have been a number of designs, which can provide direct couplingbetween an electric motor(s) mounted externally to the rear bicyclewheel and the axle of the wheel. For example, a motor can be mountedeither on the diagonal or horizontal rear members (or “stays”) of theframe. A direct coupling in these cases can be effected through a90-degree bevel gear between a shaft from the motor and the axle-hubassembly. In this case, external shocks will cause gear wear. Further,it is difficult to remove the rear wheel for repair. The drive can beeffected through a chain, which is better but still mechanically complexand subject to the same kind of problems. It is also difficult toachieve the right reduction ratios between the RPM of typical motors andthat of the rear wheel, typically between 10:1 and 25:1. A motor can bemounted above the rear wheel and drive a very large “sprocket” ofdiameter almost as large as the wheel diameter. Such systems have beendemonstrated but have not been accepted because they are clumsy,top-heavy and subject to relative dislocation of the elements.

Other direct drives have been reduced to practice with the motor mountedin the neighborhood of the pedal crank. These can be coupled to the rearwheel by a gear drive with suitable clutches within the crank housingand thence through the usual bicycle chain or through a separate longchain to a separate sprocket on the rear wheel. They can also be coupledto the rear wheel through long shafts and bevel gears. While some ofthese are workable and practical, they require a special custom bicycledesign, which may be more expensive than desired.

For designs in which a motor mounted externally to the rear wheel, animprovement is described in U.S. Pat. No. 5,934,401 entitled “PrecisionDirect Drive Mechanism for a Power Assist Apparatus for a Bicycle,” byMayer et al. filed on Feb. 20, 1997. In this concept, as depicted inFIGS. 20-23, a motor is mounted on a plate, which is separately indexedto the axle of the rear wheel. The motor drives a pinion gear (or pinionsprocket) which drives through meshed gears, a chain or a belt a targetgear (or sprocket) that is separately indexed to the axle of the rearwheel, and is attached to the axle through a bearing or free-wheelclutch arrangement. That is, the motor-pinion assembly with its mountingframe and the target gear (or sprocket) are separately indexed off theaxle, with the target gear (sprocket) actually indexed from the hub.

Thus, these elements in a benign environment are accurately aligned withrespect one another, all being indexed from presumably common andconcentric points. However, even with this improved and more compactconfiguration, we have found in practice that for most bicycles, theaxle bearing tolerances and the hub bearing tolerances are highlyvariable with real world rough usage and shocks. In more detail, if themesh between the pinion sprocket (or gear) and the target sprocket (orgear) occurs at a long leverage arm from the axle, the looseness of thebearings can change the pinion/target gear meshing or alignment, leadingto eventual gear wear, tooth breakage, or misalignments of suchsprockets. Additional concerns are the difficulty of achieving thealignment of shafts (such as the shafts of the motor, or the targetwheel) and the manufactured tolerances of components over time and withnormal rough usage.

Another class of direct drive systems are based on “hub motors” whichare designed into the wheel hubs of front or rear wheels. This class ofdrives has its own cost considerations and performance characteristics.

None of the above described electric bicycle drive propulsion systemsprovides the important advantages of the inventive unitary power modulefor an electric bicycle propulsion system which has a high degree ofmechanical integrity in the alignment geometry of the drive componentseven under shock and rough usage. These advantages are achieved byuniquely configuring the unitary power module having drive componentscomprising a drive source (or an electric motor), a pinion drivecoupling component (such as a chain sprocket, gear or pulley pinion orcombination thereof), a target mechanism coupling component (or a chainsprocket, driven gear, or belt sprocket), the actual mechanical couplingmechanism to the target or target wheel, and the target or driven wheel,itself, which is the normally the rear wheel. By use of various sprocketratios, the invention may achieve a wide-range of gear ratios andtherefore adaptability to a wide range of motors. Also, by the use of afree-wheel clutch incorporated into the unitary power module, thebicycle is completely free wheeling with virtually no drag in theabsence of applied power. Still further, when in production, the unitarypower module can be assembled and tested as an integral operating unit,and then be easily and simply attached to the bicycle frame.

Specifically, the present invention achieves these advantages byutilizing a unitary power module having mounting frame assembly on whichall propulsion elements are mounted and aligned with a wheel fitting (or“drive”) coupler, which is a disk shaped assembly with a large centeropening allowing the target coupler to be placed about a wheel axleoutside of the hub diameter. In the preferred embodiment, the targetcoupler has a groove pattern mating the woven spoke pattern of a bicyclewheel to enable the target coupler to be concentrically attached to thetarget wheel by engagement with the woven spoke pattern by securingelements. The mounting frame is attached to the target coupler by abearing or the like, including a free wheel clutch. The mounting platehas an opening (or “element”) to receive an electric motor to enable apinion sprocket or gear affixed on the motor to engage the sprocket andthrough a chain to the target sprocket (or gear) to rotate the targetbicycle wheel upon suitable power application by a rider via propulsioncontrols on the bicycle.

Thus, the present invention provides the advantages of having a separateindependent self-contained (and self-aligned) unitary power module whichovercomes misalignment problems between the drive source and the targetby using a common reference frame. The integrity of the chain alignmentor gear mesh is thereby permanently ensured even in rough terrain andrough shock and usage. This invention can thus be advantageouslyimplemented by using a chain drive, gear drive or belt drive systembecause one of its important advantages is its inherent avoidance of theusual misalignment causes by the above prior art devices. It has theadditional advantage of being easily installed on almost any bicyclerear wheel by an unique and separately described mechanical coupler. Itworks efficiently, essentially independent of frame and axle/hubassembly and wheel/hub tolerances.

SUMMARY OF THE INVENTION

According to the invention, a unitary power module for mounting apropulsion system on a bicycle comprises a mounting frame having a motorand a target sprocket integrally mounted on the mounting frame. Thetarget sprocket defines a disk shaped member having a center opening toallow the drive sprocket to be placed about a wheel axle of the bicycle.The drive sprocket mates with a bicycle wheel through a clutch andtarget coupler to enable the sprocket to be mounted substantiallyconcentrically to an axle of the wheel by engagement with a wheelpattern of the bicycle by securing elements. The mounting frame isrotatably attached to the target sprocket to allow for “aligned”rotation of the target sprocket about the wheel axle, and properalignment with an electric motor. The mounting frame has an element toreceive an electric motor to enable a pinion sprocket affixed to themotor to propel the target sprocket and rotate the bicycle wheel. In themanner, the mounting frame provides a single point of reference foraligning the pinion sprocket with the target sprocket, i.e., therebyallowing the unitary power module to operate by itself, for example on abench, independent of the bicycle per se.

In another embodiment of the invention, a propulsion system kit isprovided for converting a standard bicycle having a frame and front andrear wheel, with the rear wheel having an axle and hub together with awheel pattern into an electric bicycle. The kit comprises a batterysuitable to be affixed to the bicycle, an electric motor having a pinionsprocket (or gear) affixed thereon, with the electric motor suitable tobe connected to the battery by a battery cable. A unitary membercomprises a target sprocket, a mounting frame and gear reduction orchain mechanisms which are precisely aligned with each other. The targetcoupler sprocket comprises a disk shaped assembly having an centeropening to allow the unitary member to be placed around the axle outsidethe hub. The target coupler has a pattern which mates a pattern of therear wheel to the target sprocket to enable the target sprocket to beconcentrically attached to the wheel spokes by engagement with the spokepattern by securing elements. The mounting frame is rotatably attachedto the unitary member by a bearing or the like and has an opening toreceive the electric motor to enable the driver to engage the targetsprocket for aligned rotation of the wheel upon application by the riderof electrical propulsion controls affixed to the bicycle. The free wheelclutch can be mounted either in the motor-pinion sprocket shaft or inthe wheel attachment mechanism. Thus, the mounting frame provides asingle point of reference for aligning the pinion sprocket with thetarget sprocket.

In yet another embodiment of the invention, an electric bicyclecomprises a frame having a rider seat and propulsion controls positionedthereon. A steerable front wheel has an axle affixed to a front portionof said frame, together with a rear wheel having an axle with a wheelpattern affixed to a rear portion of the frame. A propulsion systemcomprises a battery affixed to the bicycle, and an electric motor havinga driver affixed thereon the electric motor suitable to be connected tothe battery by a battery cable. A unitary power module comprises atarget coupler and a mounting frame, with a target coupler comprising adisk shaped member having an center opening to allow the drive member tobe placed about the wheel axle. The target coupler is affixed to therear wheel to enable the target sprocket to be concentrically attachedto the rear wheel by engagement with the wheel by securing elements. Themounting frame is secured to a fixed portion of the frame in order totransmit torque and is attached to the unitary member through a bearingor the like and has an opening to receive the electric motor to enablethe driver to engage the target sprocket for aligned rotation of therear wheel upon application by the rider of the propulsion controls.Thus, the mounting frame provides a single point of reference foraligning the pinion sprocket with the target sprocket.

Preferably, in accordance with the invention, a unitary power module formounting a propulsion system on a bicycle comprises a target sprocketdefining a disk shaped member having a center opening to allow thetarget coupler to be placed about a wheel axle of the bicycle. Thetarget coupler mates a bicycle wheel to enable the sprocket to besubstantially concentrically attached to said wheel by engagement withsaid woven spoke pattern by securing elements. A mounting frame isrotatably attached to the target sprocket to allow for rotation of thetarget sprocket about the wheel axle and has an opening suitable toreceive an electric motor to enable a driver sprocket affixed to themotor to engage a second sprocket mounted by a second shaft positionedon the mounting frame. The second sprocket shaft is positioned to drivethe target coupler and rotate the bicycle wheel.

In another preferred embodiment, a propulsion system kit is provided forconverting a standard bicycle having a frame and front and rear wheels,with each having a hub, axle and a wheel spoke pattern, into an electricpowered bicycle. A battery suitable to power an electric motor isaffixed to the bicycle, together with an electric motor having a driveraffixed thereon. The electric motor is suitable to be connected to thebattery via a battery cable. An unitary power module for mounting apropulsion system on a bicycle comprises a target sprocket defining adisk shaped member having a center opening to allow the target sprocketto be placed about a wheel axle of the bicycle with the target sprocketmating the bicycle wheel pattern to enable the sprocket to besubstantially concentrically attached to the wheel by engagement withthe pattern by securing elements. A mounting frame is aligned to androtatably attached to the target sprocket to allow for aligned rotationof the target sprocket about the wheel axle and has an opening toreceive the electric motor, which enables the driver to engage a secondsprocket positioned thereon. The second sprocket is mounted on a secondshaft which engages the target sprocket to propel the target sprocketand rotate said bicycle wheel upon application by a rider of propulsioncontrols positioned on a bicycle frame. The mounting frame provides asingle point of reference for aligning the pinion sprocket with thetarget sprocket.

In yet another preferred embodiment, an electric bicycle comprises aframe having a rider seat and propulsion controls positioned andthereon. The bicycle includes a steerable front wheel having an axleaffixed to a front portion of the frame, and a rear wheel having an axlewith a pattern affixed to a rear portion of the frame. A propulsionsystem for the bicycle comprises a battery affixed to the bicycle, andan electric motor having a driver affixed thereon, the electric motorsuitable to be connected to the battery by a battery cable. A unitarypower module for mounting a propulsion system on the bicycle comprises atarget sprocket defining a disk shaped member having a center opening toallow the target sprocket to be placed about a wheel axle of thebicycle. The target sprocket mates with a bicycle through a wheelcoupler to enable the target coupler to be substantially concentricallyattached to the wheel by engagement with the wheel pattern by securingelements. A mounting frame is aligned and rotatably attached to thetarget sprocket to allow for aligned rotation of the target sprocketwith the driver about the wheel axle and has an opening to receive theelectric motor to enable the driver affixed on the motor to engage asecond sprocket positioned on a shaft. The second sprocket shaft isdisposed to engage the target sprocket to propel the target sprocket androtate the bicycle wheel upon application by a rider of propulsioncontrols positioned on the bicycle. The mounting frame provides a singlepoint of reference for aligning the pinion sprocket with the targetsprocket.

Preferably, the above embodiments having the second sprocket and shaftinclude a third sprocket concentrically mounted upon with the secondshaft, with the driver rotating the second sprocket, which in turnrotates the third sprocket which is positioned to engage the targetsprocket.

In more detail, and by way of example, the target sprocket is preferablyattached to the mounting frame by a bearing. Further, a one way clutchis affixed between the pinion sprocket and the motor.

Still further, the target coupler (or target sprocket) may include agroove pattern disposed to mate a woven spoke pattern of the bicyclewheel, or simply mate with a hub positioned on the bicycle wheel.

Further, the pinion sprocket may engage the target sprocket (or secondsprocket and third sprocket as appropriate, by either the targetsprocket and driver each having a plurality of teeth suitable to beconnected in power engagement a drive chain; or each having a pluralityof gear teeth suitable to be engaged by one another, or each having asurface suitable to be engaged by a drive belt.

Furthermore, the electric motor may quickly be engaged or released fromthe mounting frame by a series of quick release tabs, together withconnecting or disconnecting the motor shaft with a unitary power moduleshaft by using gears or spline connections.

According to the invention, a disk shaped member for an electric bicyclepropulsion system preferably comprises a target sprocket comprising adisk shaped assembly having an center opening to allow target sprocketmember to be placed about a wheel axle, and woven spoke pattern whichallows the target sprocket to mate the woven spoke pattern of a wheel toenable the sprocket to be concentrically attached to the wheel outsidethe hub diameter by engagement by securing elements.

Further, a mounting frame for an electric bicycle propulsion system hasa first and second opening disposed to receive an electric motor, andtarget sprocket, respectively. The target sprocket is securable to abicycle wheel and securable to the mounting frame about a bearingaffixed about the second opening.

As pointed out in greater detail below, the embodiments of thisinvention provides a number of significant advantages. For example, thekey points of the invention include the establishment of a commonreference or mounting frame and structure which assures precisionalignment for the entire propulsion system under all conditions. Thisreference frame is formed by the disk or target sprocket along with thehollow extension collar and grooved surface. This disk provides a solidmounting attachment with the wheel through the grooved surface matingwith the wheel hub and spokes. The disk is held concentric with thewheel hub, but great eccentricity accuracy is not required. The sprocketgear is attached to the reference frame disk through either afreewheeling clutch or directly attached to the reference frame disk.The motor mounting frame is attached to the reference frame disk througha bearing on the hollow extension collar of the disk. The motor isattached to the motor mounting frame, in such a way as to provide forproper meshing of the driven and target sprocket, independent of axleand hub bearing tolerances. The driver sprocket (or gear) is attached tothe motor either directly, or through a one-way roller clutch, dependingon whether the driven (or sprocket) gear has a freewheeling clutch. Inthis manner, the pinion sprocket, target sprocket and any intermediategears are precisely aligned irrespective whether they are interconnectedby a chain, a gear, or a belt. The motor mounting frame is clamped tothe bicycle frame to prevent rotation of the mounting frame, i.e., totransmit propulsion torque to the bicycle.

The invention holds the entire propulsion system within the samereference frame, thereby constraining the propulsion system toleranceswithin the propulsion system. These tolerances are determined by themanufacturing tolerances of the propulsion system components as designedindependent of the vehicle manufacturing tolerances. This allows thepropulsion system to be applied to any vehicle, while maintaining theintegrity and performance of the propulsion system. The inventionitself, together with further objects and attendant advantages, willbest be understood by reference to the following detailed descriptiontaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an inside side view of the present invention illustrating apreferred “chain-drive” embodiment of the unitary power module showingthe mounting frame with the motor, pinion sprocket, chain and targetsprocket.

FIG. 2 is a illustrative cross sectional view of taken generally alongthe axis of the motor of FIG. 1.

FIG. 3 is a cross sectional illustration view taken along the axis ofthe bicycle wheel showing a preferred embodiment of the mounting frameof the present invention mounted thereon.

FIGS. 4(a) and 4(b) are cross sectional illustration view taken alongthe axis of the bicycle wheel showing the mounting frame of otherembodiments of the present invention mounted thereon.

FIGS. 5(a) and 5(b) are outside and inside side views of the mountingframe of the unitary power module of the present invention using a gearconnection without the motor mounted thereon, and FIG. 5(c) is anenlarged view of the annular target coupler pattern suitable to engagethe 36 spoke 3 cross wheel pattern of a bicycle wheel.

FIGS. 6(a) and 6(b) are outside and inside side views of the mountingframe of the unitary power module of the present invention using a chainconnection along with an electric motor, pinion gear sprocket, targetsprocket and electrical connector.

FIG. 7 is an outside side perspective view of the mounting frame andtarget coupler of the unitary power module of the present inventionmounted on a bicycle rear wheel.

FIG. 8 is an outside side perspective view of the unitary power moduleof the present invention using a chain connection mounted on a bicyclerear wheel.

FIG. 9 is an inside side prospective view of the unitary power moduleusing a pinion sprocket and target sprocket using a chain connectionattached to the rear wheel of bicycle.

FIGS. 10(a) and 10(b) are cross-sectional views of other preferredembodiments of the unitary power module using a second sprocket andshaft used to achieve reduction in motor Revolutions per Minute (“RPM”).

FIG. 11 is an illustrative side view partially in cross-section of theunitary power module of FIG. 10(a).

FIG. 12 is another embodiment of a unitary power module having first andsecond motors with pinion gears to provide power to the unitary powermodule.

FIG. 13 illustrates an alternative embodiment of mounting a motor on amounting frame using a bevel gear.

FIG. 14 is a side elevational view of a propulsion system kit for anelectric bicycle of the present invention shown in solid lines, with theexisting bicycle illustrated in shadow lines.

FIG. 15 is a side elevational view of an electric bicycle of the presentinvention.

FIGS. 16(a), 16(b), 16(c), 16(d), 16(e) and 16(f) are illustrative crosssectional views of alternative embodiments of target coupler suitable tomate the target sprocket to a bicycle wheel.

FIG. 17 is a cross sectional view of a quick disconnect motor mountwhich may be used with the unitary power module using a gear drive.

FIGS. 18(a), 18(b) and 18(c) further illustrate the motor mountingsystem of FIG. 17 in a locked and an unlocked position.

FIG. 19(a) is a side elevational view of a standard bicycle, and FIG.19(b) is an enlarged view of the opposite side of the rear wheel of FIG.19(a)

FIG. 20 is a rear view of a motor and target gear (or sprocket) that areeach separately indexed off of the same axle and interconnected viameshing gears.

FIG. 21 is side view of a motor and target gear (or sprocket) that areeach separately indexed off of the same axle and interconnected via achain.

FIG. 22 is a rear view of a motor and target gear (or sprocket) that areeach separately indexed off of the same axle and interconnected via abelt.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-3, a key aspect of the unitary power module 200(or “unitary propulsion module”) concerns the providing of a one frameof reference to align a pinion sprocket to a target sprocket. This isaccomplished by using a “mounting frame” 204 of the unitary power module200 to accurately align a pinion sprocket 242 of an electric motor 230to the wheel/hub assembly 140 (shown in FIGS. 3 and 19). As all driveand target elements of the unitary power module are mounted to themounting frame 204, a single integral and independent point of referenceassures their proper alignment. The attachment of the mounting frame 204to the hub/spoke assembly 140 (and to the bicycle frame) allows for astable reference frame, since the wheel/hub assembly 140 is attacheddirectly to the tire/rim assembly 128 of the wheel 104 (which is thetarget drive mechanism of the unitary power module 200). As describedhereinafter, this reference frame eliminates the loose or varyingtolerances of the wheel/hub assembly 140 and the tire/rim assembly 128and the axle 118 and frame assembly 106, thereby providing rigidalignment of the drive and target elements of the unitary power module200 even with the attendant shock and wear incumbent in such drivesystems.

Turning now to FIG. 1, in one of the preferred embodiments of theinvention, the mounting frame 204 is connected to a motor having apinion sprocket 242 mounted thereon which is interconnected via a chain211 to a target sprocket 202 with a target coupler 203 having a pattern205 (shown in FIG. 5(b)) which matches the woven spoke pattern 130 ofthe bicycle wheel (shown FIG. 19). An idler sprocket (or gear or pulleyor “idler”) 288 may be used to provide tension between a chain 211 toensure engagement between the pinion sprocket 242 and the targetsprocket 202. The idler 288 can also be used to allow the chain 211 toengage more teeth of the pinion sprocket 242 and thus permit closerspacing between the pinion sprocket 242 and the target sprocket. Themounting frame 204, when attached directly to the target sprocket 202through a bearing 206, such as a ring bearing, allows the referenceframe of the target sprocket 202 to freely rotate within acceptabletolerances while maintaining its mechanical attachment to the mountingframe 204. Further, the mounting frame 204 includes a motor opening 224shown in FIGS. 2 and 3 (or other mechanical element for attachment) fora motor 230 to be positioned thereon.

FIG. 2 illustrates the position of the motor 230 having a motor shaft244 which engages a planetary gear 246 suitable for gear reduction, suchas from 5:1 or 7:1 RPM reduction. By use of a this importantconfiguration, the planetary gear reduction system between the motorshaft 244 and pinion sprocket 242 enables the user to select thepreferred overall RPM ratio between motor and bicycle wheel, which canbe adjusted over a wide range of high values. The planetary gear 246 inturn engages the pinion sprocket 242, which is interconnected by a chainto the target sprocket. This simple configuration will be the least costof certain applications. The overall reduction ratio between the RPM ofthe motor 230 and the RPM of bicycle wheel 104 is easily adjusted by theratio of diameters or number of teeth between the pinion sprocket 242and target sprocket 202. A quick-disconnect 500 for the motor 230 isprovided by providing a spline 245 on the motor shaft 244 attaching tothe input of the planetary gear system 246. Of course, in a stillsimpler configuration the planetary gear reduction is not needed. Forexample, the motor 230 may connect directly to the pinion sprocket andthe overall RPM ration between the motor 203 and the drive wheel 104(not shown) is smaller. In this case, a lower RPM motor is necessary.

As further illustrated in FIG. 3, the mounting frame 204 receives themotor 230 having its motor shaft 244 perpendicular to mounting frame204. Through the mechanism such as illustrated in FIG. 1, the motor 230is suitable to provide power to the pinion sprocket 242. The targetsprocket 202 is affixed to a hollow extension collar (or rotating tube)207 or the like, which is interconnected a target coupler 203, whichengages the spokes 124 of the bicycle wheel 104 about the hub 122 butmounts to the spokes 124 outside of the hub 122. The target coupler 203has the same wheel spoke pattern 205, as shown in FIG. 5(c), to mate thewheel spoke pattern 205 of the bicycle wheel 104 shown in FIG. 8. Theinner diameter of this whole assembly is made large enough to fit overvirtually all types of hubs 122. The coupler fastens to the spokes andspreads the torque across typically 16 or 18 spokes at their strongestpoint. This target coupler 203 is rigidly connected to (or part of) therotating tube 207, which can rotate with respect to the mounting frame204 because of the ring bearing 206. Thus, as described, the inventionprovided a common point of reference for the various components of thedirect drive system, which allows tolerances to be controlled within thepropulsion drive system, as well as isolated from the tolerances of thebicycle components. Merely by way of example, the target sprocket 202and target coupler 203 (or “criss-cross coupler”) may be constructed ofeither aluminum or engineered plastic which can be molded, and themounting frame 204 is preferably aluminum, both for light weight andrelatively high thermal conductivity for the purpose of dissipatingmotor heat.

As pointed out above, the target sprocket 202, which preferably isdriven by a chain 211 from the pinion sprocket 242, is mounted through afreewheeling clutch 277 proximate to the rotating tube 207. The freewheel clutch allows the wheel to spin freely without the drag of theelectric motor 230, when the electric motor is not being powered. Thisfree wheel clutch 277 significantly reduces wheel drag, a discernibleeffect to the bicycle rider, and improves the range of the bicycle. Thefree wheel clutch 277 can be implemented as a roller clutch or“freewheel” on the pinion sprocket gear or as a free wheel clutch on thetarget sprocket. In this manner, when the target sprocket rotates fasterthan the rear wheel, it engages and drives the wheel. When coasting withthe motor off, the free-wheel allows the rear wheel to rotate with thetarget sprocket 202 disengaged.

A suitable “freewheel” or “one-way roller” clutches which may beincorporated into the unitary power module 200 is a Dicta BrandFreewheel manufactured by Lida Machinery Co., Ltd., Tao Yuan, Taiwan,and is a freewheel which employs pawls in the clutch. It is positionedin the target sprocket, which drives the rear wheel. It is incorporatedinto the gear or sprocket and is concentric with the wheel axle as partof the mechanism. Another suitable unit is a roller clutch made byTorrington, Inc. of Connecticut which can be incorporated on theintermediate shaft on which is mounted two sprockets in the two-stagegear reduction configuration. As described hereinafter, there areseveral methods for implementing a one-way clutch feature for thepropulsion system, e.g., one possible way would be to put a rollerclutch between the motor and pinion gear. An alternate mechanizationwould be to put a freewheeling clutch between the wheel and the targetsprocket or gear. If the freewheeling clutch is placed between the wheeland driven gear, then the freewheeling clutch would attach to the hollowextension collar of the reference frame disk already described.Otherwise, if a one-way clutch is implemented between the motor andpinion gear the driven gear would be directly and firmly attached to thedisk and hollow extension collar.

As illustrated, a ring bearing 206 allows the mounting frame to rotatearound a tube, which can rotate. The rotating tube 207 is rigidlyattached to the target coupler 203 (or spoke coupler or target coupler,which as illustrated is a disk shaped member which is circular with thetube 207 (or a hollow collar) in the center. The bearing 206 attaches toand interconnects the target sprocket 202 having the hollow collar 207at a centrally positioned opening 208 of the target sprocket 202 and anopening 210 of the mounting frame 204, which are concentric to oneanother. The target coupler 203 that drives the bicycle wheel is a diskshaped member having the central opening 208 and an outside and insidesurface 212, 214. In this embodiment, the target sprocket 202 includes aplurality of chain teeth 216 suitable to engage the chain 211. Thehollow collar 207 allows clearance of the axle of the wheel 104. Thefree-wheel clutch (or “free wheel”) can also be mounted as beforedescribed or either on the target sprocket-coupler mechanism or theoutput shaft of the planetary gears 246.

The target sprocket 202 is mounted about the rotating tube 207 by thefreewheeling (“free wheel”) or the one-way clutch 277. The free-wheel277 can be mounted on the motor shaft 244 between the pinion sprocket242 and the motor shaft 244. As illustrated, when the motor 230 is offand the shaft is stationary, the pinion sprocket 242 can rotate alongwith the chain 211. The rotating tube 207 is precisely mounted to themounting frame 204 by a ring bearing 206 or the like concentric with therear axle. The mounting frame 204 is mounted to the bicycle frame 106 bysuitable securing elements 235, as shown in FIGS. 14, 15. For example,as may be understood from FIGS. 14 and 15, the quick disconnect (or“quick-disconnect clamp”) may affix the mounting frame 204 to thebicycle frame 106 (via either the horizontal or diagonal rear stays 112)in lieu of securing element 235. In this manner, the torque from thepropulsion system is transmitted to the rear wheels, which of course,eliminates any rotation between the mounting frame 204 and the bicycleframe 106. When the motor 230 is off, the target sprocket 202 isstationary and the tube-coupler-bicycle wheel can rotate because of theaction of the free-wheel 277. When the motor 230 is on, i.e., the targetsprocket 202 is rotating faster than the coupler-bicycle wheel, the freewheel 277 engages and the target sprocket 202 drives thetube-coupler-bicycle wheel assembly.

As described in FIGS. 1-3, the entire unitary power module 200 istotally independent of the bicycle per se as it can be operated byitself, e.g., on a bench. The mounting frame provides and maintainsrigid alignment of the complete propulsion module independent ofbicycle-hub-axle tolerances. The unitary power module, when attached tothe spokes, can even be somewhat off-center with respect to the axlewith little noticeable effect. Further, as shown in FIGS. 14 and 15, theunitary power module 200 may be attached to the frame by thequick-disconnect 234 to assure easy repair or replacement of a tire orthe module itself.

Turning now to FIGS. 4(a) and (b), the invention may be practiced whenthe target coupler 203 and target sprocket 202 are formed in an integralunit. Further as illustrated in FIG. 4(b), a belt 278, such as a “V”belt 278 may be used rather than a chain to interconnect the pinionsprocket 242 and target sprocket 202. As illustrated, a “V” groove 284is formed in both the pinion sprocket 242 and target sprocket 202 (andidler sprocket 288) to receive the “V” belt. Similarly, the targetsprocket 202 defines a similar surface groove 286 to receive a “V” belt278 or the like. Other forms of belt configurations may readily be usedby modifying the pinion sprocket 242 and target sprocket 204 to receivesuch belts 278.

Merely by way of illustration, FIGS. 5(a) and 5(b) show anotherembodiment of the unitary power module 200 suitable for using meshedgears (with the pinion gear in phantom lines) when viewed from the“outside” of the bicycle 100. Meshed gears, in contrast to a chain andsprocket, have the advantage of being very compact and may function verywell with this rigid alignment concept of the mounting frame 204. Inthis embodiment, the pinion sprocket 242 (shown in a phantom line) orpinion pulley must be located closer radially towards the axle hole sothat appropriate engagement is maintained between a pinion gear and thetarget sprocket. Also, the motor rotates in the opposite direction tothat for the chain drive. As described, the mounting frame 204 andtarget sprocket 202, which are aligned together with a free wheel clutch277 placed therebetween. The mounting frame 204 is mounted to the targetsprocket 202, though an opening 210 in the mounting frame 204, by way ofan attachment to a hollow extension tube 207 or collar 207 (“tube 207”)of the target sprocket 202, which is mounted to the bicycle wheel 104,as described below. A projection 209 may be formed on the mounting plate204 to secure the mounting plate 204 via a clamp or the like to theframe assembly (not shown).

Turning to FIG. 5(b), the inside surface 214 (not shown) of the otherside of the target sprocket 202 includes an annular region 218positioned generally concentric on the target sprocket opening 208. Theannular region 218 includes a plurality of crossed slots 220, which fitthe spoke pattern of a standard bicycle wheel (e.g., such as the commonconfiguration of 36 spokes or 34 spokes, half on each end of hub 122). Aplurality of tapped holes 222 are spaced around the annular region 218which serve the purpose of receiving screws (not shown) to fasten thetarget coupler 203 to the wheel spokes 124. Alternatively, studs (notshown) may take the place of holes which match a plate (not shown, butillustrated in FIG. 6((b)). The mounting frame 204 defines a secondopening 224 to receive an electric motor (not shown). As illustrated inphantom lines, the pinion sprocket 242 (S1) is positioned to engage thetarget sprocket 202. An enlarged view of the annular target couplerpattern suitable to engage the spokes 124 of a 36 spoke 3 cross wheelpattern of a bicycle wheel is shown in FIG. 5(c). As illustrated, thetarget coupler 203 includes crossed slots 224 are formed to receive thespokes 124 of the bicycle wheel thereby providing a firm mechanicalcoupling of the target coupler 203 to the bicycle wheel (not shown).

While FIGS. 5(a) and 5(b) illustrate a meshed gear drive system, a chaindrive system as described above would involve only moving the pinionsprocket away from the sprocket 202 and use teeth rather that the gearson the target sprocket 202. As described above, the motor in a chaindrive would rotate the opposite direction than a meshed gear drive toimpart the same rotational direction to the bicycle wheel.

As illustrated in FIG. 6(a), the unitary power module 200 is shown ashaving an electric motor (or motor) 230 as it would look from “outside”of the bicycle wheel if it were attached to the wheel (not shown). Asuitable electric motor 230 for use with this invention is a brushlessdc motor having a R.P.M. operational speed from about 3000 R.P.M. toabout 4000 R.P.M. along with integral control electronics. Brush motorsof a wide variety can also be used. Other motors with a wide range ofoperational RPM's can be employed with the various reduction mechanismstaught herein. The motor 230 has an electrical cable 232 suitable toplug into a module connector 231 for interconnection to a battery. Asillustrated above, the target sprocket 202 is mounted on the mountingframe 204 in the second opening 224 provided therein. The large diameterof the opening 210 in the mounting frame 204 is suitable for it to slipover the entire wheel/hub assembly 140. The motor 230 may be quicklyattached to the mounting frame 204 by quick release tabs 234, and may bequickly removed by rotation of the tabs 234 or other similar quickdisconnect fasteners. As illustrated, the pinion sprocket 242 is coupledby the chain 211 with the target sprocket 202.

In this manner, the motor 230 can be quickly removed or replaced merelyby releasing the tabs 234 and disconnect the electrical cable 232 fromthe module connector 231 within the motor 230. Turning now to FIG. 6(b),the target sprocket 202 is mounted on the opposite side of the mountingframe 204 from the motor side. Since this is an integral “unitary powermodule,” the pinion sprocket 242 (“S1”) and target sprocket 204 (or“S4”) remain perfectly meshed or aligned with each other whether or notthe module is exactly concentrically attached to the bicycle wheel 104and independent of any loose tolerances and changing tolerances of thehub or bearings.

Furthermore, in cases where the bicycle wheel is warped or if it isotherwise in less than in a planar configuration, the alignment of thechain between the pinion sprocket 242 and target sprocket is accuratelymaintained. FIG. 6(b) also illustrates the use of the mounting ring 236to secure the target coupler 203 to the bicycle wheel hub 122. Theinside surface 214 of the other side of the target coupler 203 includesan annular region 218 which is concentric with the target sprocketopening 208. The annular region has crossed slots 220 which fit thespoke pattern 130 of a standard bicycle wheel (not shown). The holes 222are positioned in the annular region 218. The crossed slots 220 fit thespoke pattern 130 of the bicycle wheel, such as the rear wheel of FIG.19.

In FIG. 7, the target module 204 is shown in combination with the targetsprocket 202 having the target coupler 203 (shown in phantom lines)engaging a thirty-six spoke, three cross wheel pattern of a bicyclewheel. A suitable material for construction of the target coupler 203would be Al 6061 having a black anodize or the like, or it could be madeof a plastic along with molded metal thread inserts. By preciselyintegrating the woven pattern 130 of a spoke wheel, the target coupler203 provides a rugged construction suitable to receive the torque loadsimposed upon the target sprocket 202.

Turning now to FIG. 8, the unitary power module 200, with a motor 230and pinion sprocket 242 using the chain 211 to drive the target sprocket202, is shown in an “outside” side view attached to a bicycle wheel 104.The bicycle wheel 104 includes an axle 118, a hub 122, a plurality ofspokes 124 positioned about the axle 118 (as further illustrated inFIGS. 16(a)(b)(c)), and connecting to the tire/rim assembly 124. Themounting frame 204 and target sprocket 202 are mounted around the axle118 though the target sprocket opening 208 and plate opening 210respectively on the target sprocket 202 and mounting frame 204. Asillustrated above, the unitary power module 200 includes a plurality ofquick-release fittings, such as the tabs 234, the motor 230 can bequickly detached from the mounting frame. When re-engaged, accurate gearalignment is automatically established. This feature providessignificant advantages, as it is useful both for easy repairs(replacement) and for converting the bicycle back and forth betweenelectric and conventional configurations. Also, a one-way roller clutch240 can either be concentric with the target sprocket 202 and bearing206 or it can be attached to a pinion sprocket 242 on the motor. As isapparent, this is a complete propulsion module or “kit” to convert abicycle into an electric bicycle. That is, if voltage is applied to themotor, the motor can drive the pinion sprocket, which in turn can drivethe larger target sprocket 202, and it works as a unitary self-containedmodule. Further, this unitary power module 200 can be attached to theouter diameter of the bicycle wheel hub 122. The mounting frame 204 iseasily rotated around the wheel axle for any position to attach to theframe 106 which does not interfere with the bicycle frame stays 112.

As illustrated from the “inside” perspective in FIG. 9, the unitarypower module 200 with the motor 230 and pinion sprocket 242, is mountedto the bicycle wheel 104, with the spokes 124 and the hub 122 by amounting ring 236. Merely for illustration, the “inside” shows aderailleur gear cluster 156, having a plurality of sprockets 156, 158,160, 162, 164, and 166 suitable for manual gear adjustment. As describedabove, FIG. 9 shows the attachment of the target coupler 203 (or targetsprocket 202) connected or meshed with bicycle wheel 104 in thefollowing manner. The mounting ring 236 formed by two semi-circularpieces 238,239 fits flush against the target sprocket 202 and secures itto be positioned to receive the spokes 124. A plurality of screws 249(or bolts where the holes 222 are replaced with studs) or the like,extend through the wheel spokes 124 then secure the target sprocket 202as a unit to the bicycle wheel 104. As a result the target sprocket 202attaches firmly and precisely with the wheel/hub assembly of the wheel104. The target sprocket 202 through virtue of the grooves holdsprecisely to the wheel 104, maintaining concentricity with the wheel/hubassembly, although perfect concentricity is not required. In thismanner, the target sprocket 202 can rigidly be mounted to the spokes 124of a bicycle wheel 104. The mounting ring 236 includes a plurality ofholes 270 which mate to the holes 222 of the annular region 218 of thetarget sprocket 202, as shown in FIG. 5.

It is important to recognize that the unitary power module 200 isautomatically centered to reasonable and practical tolerances on theaxle of the bicycle 100 to a fairly close tolerance. Perfect centeringis not required for perfect pinion-driven gear alignment, which isindependently maintained on the unitary self-contained module. It isimportant to note that the plate opening 210 in the mounting frame ismuch larger than the wheel axle and hub diameter. Thus, the whole unitcan be rotated around the axle for a convenient angular position withrespect to the members of the bicycle frame 106. The mounting frame 204is then connected to the frame by a strap or pin 235, as shown in FIG.14 or a quick-disconnect clamp such a “C” clamp (not shown). This isnecessary to hold the position of the unit with respect to the frame 106and to transfer the torque to the frame. As this connection can be thequick disconnect clamp, it facilitates rapid disconnection of module 200from the frame 106 and rapid wheel/tire repair.

Turning now to FIGS. 10(a), 10(b) and 11, another preferred embodimentof the unitary power module of the present invention is illustrated. Inthis embodiment, unitary power module includes a the target sprocket 202(“S4”) defining a disk shaped member having a center opening 210 toallow the target sprocket 202 to be placed about the wheel axle 118 ofthe bicycle. As before, the target sprocket 202 mates with a bicyclewheel 104 to enable the target sprocket 202 to be substantiallyconcentrically attached to the wheel by engagement the woven spokepattern 130 by the target coupler 203 and the securing elements asdescribed above. The mounting frame 204 is aligned with and rotatablyattached to the target sprocket 202 to allow for rotation of the targetsprocket 202 (“S4”) about the wheel axle 118. The mounting frame 204 hasan opening 224 to receive an electric motor 230 to enable a pinionsprocket 242 (“S1”) affixed via motor shaft 244 of the motor 230 toengage a second sprocket 250 (“S2”) via the chain 211. The mountingframe 204 includes the projection 209 which enables the mounting frame204 to be secured to the frame. The second sprocket S2 is mounted by asecond shaft 252 positioned on the mounting frame 204, is aligned withthe pinion sprocket 242. The third sprocket 264 (“S3”) is also mountedon the same second shaft 252 as sprocket S2, and is aligned with thetarget sprocket 202. The third sprocket S3 is positioned to engage thetarget sprocket 202, such as via the chain 276, and rotate targetsprocket 202 thus rotating bicycle wheel 104.

In this “2-chain” embodiment there are two sprockets, S2 and S3 mountedon an intermediate shaft. The motor drives pinion sprocket 242 (S1)through the first chain 211. Sprocket S2, which is usually larger thanS1, in turn drives S3 and the final target sprocket 202 (S4) by a secondchain 276. While the sprockets S1, S2 are on one side of the mountingframe 204, and sprockets S3 and S4 are illustrated on the other side ofthe mounting frame, the pair of sprockets S1, S2 and S3 and S4 can be invarious positions in regard to the mounting frame 204, e.g., S1 and S2may be on the same side of the mounting frame 204 with S3 and S4. By useof the two chain drives, the overall gear ratio can easily be adjustedby arranging the number of teeth on S1, S2 (or the other sprockets).Also, in a like manner, two or more belt drive systems may also be used.Accordingly, this can provide great flexibility and compactness asdifferent motors having different costs, RPM's, etc., can be easilyadapted as the power sources. As described, it is apparent that thisconfiguration is elegant and very compact. Also, in this case, thefree-wheel 277 can either be mounted concentric with the axle betweenthe target sprocket 202 and coupler 203 or, e.g., on the intermediateshaft between S-1 and S-2.

In another embodiment of the invention, as illustrated in FIG. 12, themounting frame 204 additionally may include a second opening 270 (notillustrated) suitable to receive a second electric motor 272 having asecond pinion sprocket 274. The second pinion sprocket 274 can beconnected to the pinion sprocket 242 in a manner that target sprocket202 is driven by both electric motors 230, 272. For example, the pinionsprocket 242 and the second pinion sprocket 274 are connectable andaligned together by a chain 276 to provide rotational power to thetarget sprocket. Also, one of the motors 230 may include a one-wayroller clutch 240 and the other electrical motor 272 may include aroller clutch. In this manner, one motor can be shut off while the othermotor is operating for level riding, however, for steeper grades thesecond motor can be switched on to effectively double the availablepower to the target sprocket and the bicycle wheel. As understood, oneor more independent integral propulsion modules can be mounted to abicycle, thus providing optimum performance of torque and efficiency atrelatively low RPM.

In another embodiment of the invention shown in FIG. 13, the motor 230is mounted on mounting frame 204 in a parallel (or horizontal) positionto major axis of the mounting frame 204. By use of a pair of bevel gears290, 292, power from the motor 230 is supplied to the target sprocket.By use of this configuration, a cylindrical motor 230 whose axis isparallel to the plane of the mounting frame may be used. The bevel gears290, 292 which transmit rotation of a shaft parallel to the mountingframe to a shaft perpendicular to the plate, can work reliably withshock and vibration because of the rigid “unitary” assembly. All otherpropulsion elements are the same. This provides additional ability toadapt to longer cylindrical motors rather than pancake designs. In thismanner, the breadth of the motor projection can be minimized and anothermotor having an extended cylindrical shape can be used without havingthe motor projecting a substantial horizontal distance.

Another embodiment of invention is shown in FIG. 14, which illustrates akit 299 for converting a standard bicycle (shown in phantom lines) to anelectric bicycle, which is easily connected and disconnected from anybicycle. It permits simple dropping of the rear wheel for wheel and tirerepair. By use of this kit, the unitary power module can be easilymounted or attached to the outside diameter (“O.D.”) of a bicycle wheelhub, fitting virtually any bicycle and transforming it quickly into ahigh-performance electric bicycle. In more detail, the propulsion systemkit is provided for converting a standard bicycle having a frame 106 andthe front wheel 102 and the rear wheel 104, with the rear wheel 104having an axle 118 and hub 122 together with a wheel pattern (or wovenpattern) 130 into an electric bicycle. The kit 299 comprises a battery300 suitable to be affixed to the bicycle 100, an electric motor 230having a pinion sprocket gear 242 affixed thereon, with the electricmotor 230 suitable to be connected to the battery 300 by a battery cable232. Propulsion controls 328 are attached to the handlebars 109 forspeed control. These components together with the above unitary member200, and all of the above described components comprises the “kit,”which can convert any standard bicycle into a high performance electricbicycle.

Also, as illustrated in FIG. 14 (and FIGS. 6(a), (b), and FIG. 8 above),the kit 299 provides the components of the unitary power module 200,including the electric motor 230 which attaches to the mounting frame204. The attachment of the motor 230 allows for the pinion gear 242 toproperly mesh with the target sprocket 202 affixed to wheel of anystandard bicycle by the target coupler 203, independent of axle bearingand hub bearing tolerances. A mounting frame clamp 235 is attached tothe projection 209 of motor mounting frame 204, to prevent the motor 230and mounting frame 204 from rotating about the frame assembly 106 andthus provide a stable mounting point for the unitary power module.Alternatively, the clamp 235 may be replaced with the quick disconnectelement previously suggested (such as quick disconnect 234 shown inFIGS. 18(a), (b) and (c)) so that entire rear wheel/unitary power modulewheel can be rapidly dropped for tire/wheel repair. This quickdisconnect is similar to the quick disconnect fitting which clamps thebicycle wheels to the dropouts on the bicycle frame.

As illustrated above, the unitary power module 200 includes a pluralityof quick-release fittings, such as the tabs 234, the motor 230 can bequickly detached from the mounting frame. When re-engaged, accurate gearalignment is automatically established. This feature providessignificant advantages, as it is useful both for easy repairs(replacement) and for converting the bicycle back and forth betweenelectric and conventional configurations. Also, a one-way roller clutch240 can either be concentric with the target sprocket 202 and bearing206 or it can be attached to a pinion sprocket 242 on the motor. As isapparent, this is a complete propulsion module or “kit” to convert abicycle into an electric bicycle. That is, if voltage is applied to themotor, the motor can drive the pinion sprocket, which in turn can drivethe larger target sprocket 202, and it works as a unitary self-containedmodule. Further, this unitary power module 200 can be attached to theouter diameter of the bicycle wheel hub 122. The mounting frame 204 iseasily rotated around the wheel axle for any position to attach to theframe 106 which does not interfere with the bicycle frame stays 112.

In another embodiment of the invention illustrated in FIG. 15, anelectric bicycle 400 comprises a frame 106 having a rider seat 115 andpropulsion controls 328 positioned thereon. A steerable front wheel 102via the handle bars 109 has an axle 118 affixed to a front portion ofsaid frame 106, together with a rear wheel 104 having an axle with awheel pattern affixed to a rear portion of the frame. A propulsionsystem 400 comprises a battery 300 affixed to the bicycle 400, and anelectric motor 230 having a pinion sprocket 242 affixed thereon theelectric motor 230 suitable to be connected to the battery 300 by abattery cable 232. These components, together with the above-describedunitary power module, comprise the electric bicycle 400 in accordancewith the present invention.

As illustrated in FIGS. 16(a), (b), (c), (d), (e) and (f) the practiceof the invention of FIG. 15 (and of FIGS. 1-14) is not limited to atarget coupler 203 having a “criss-cross” spoke pattern, but may use avarious embodiments of a target coupler 203 for transferring rotationalpower to the rear wheel and provide an independent self-aligned system.Turning now to FIGS. 16(a), (b) and (c), with like numerals illustratinglike elements, the hub 122 rotates around a bearing assembly 126. Thehub 122 has a “extended” flange 514 having a sufficient annularextension to form a plurality of openings 516 about the flange 514 toreceive securing elements 518, such as studs, bolts, screws or like,positioned in a matched plurality of openings 522 on or within thetarget sprocket 202. In this manner, the target sprocket 202 incombination with the elements 518 form the target coupler 203. In thisembodiment, the free wheeling clutch 277 is positioned on the pinionsprocket 242.

Turning now to FIG. 16(b), the free wheel clutch is positioned betweentarget sprocket 202 and hub 122. The hub 122 has extended flanges 532,534 which are proximate or adjacent to target sprocket 202 and hubflange 514, respectively. Securing elements 518, such as studs, bolts,screws or like, positioned in a matched plurality of openings 522 on orwithin the target sprocket 202 mate with a plurality of openings 536 inthe free wheel flange 532. Securing elements 540, such as studs, bolts,screws or like, positioned in a matched plurality of openings 538 on orwithin the free wheel flange 534 mate with a plurality of openings 522in the target sprocket. In this manner, the combination of the targetsprocket 202, the flanges 532, 534 on the free wheel clutch 277 andsecuring elements 518 and 540 form the target coupler 203.

FIG. 16(c) shows a double ended hub 550 having a pair of free wheelclutches 277 on the outside of each extended hub flange 514 of theflange 122 with the target sprocket 202 placed in an annularconfiguration about the free wheel clutches 277. The free wheel clutches277 are affixed to the axle by use of a thread 552 positioned thereon.In this manner, the combination of the target sprocket, free wheelclutches 277 and axle thread 552 form the target coupler 203. Asillustrated in FIGS. 16(a), (b) and (c) the practice of the invention ofFIG. 15 (and of FIGS. 1-14) is not limited to a target coupler 203having a “criss-cross” spoke pattern, but may use a various embodimentsof a target coupler 203 for transferring rotational power to the rearwheel and provide an independent self-aligned system.

Turning now to FIG. 16(d), the hub 122 rotates around a bearing assembly126 mounted on the axle 118. The hub 122 has an “extended” hub flange514 having a sufficient annular extension to accommodate a plurality ofopenings 522 (or holes) to receive securing elements 518, such as studs,bolts, screws, or the like, positioned in the matched plurality ofopenings 522 on or within the target coupler 203. The target coupler 203consists of the target sprocket 202 fixed to an adapter ring 521 which,together, constitute the “target coupler” 203. As illustrated in FIGS.16(a) and (b), the target sprocket 202 is driven by a chain from thepinion sprocket driven by a motor mounted on the mounting plate 204. Thetarget coupler 203 is thus attached to the hub flange 514 with theelements 518, illustrated as screws in FIG. 16(d). A bearing carrier 524secures the bearing 206 (or main bearing) which allows the backing ormounting plate 204 to rotate with respect to the target coupler 203 andthe hub 122. A clamp plate 519 secures the bearing carrier 524 andmounting plate 204 to the target coupler 203. Alternatively, a freewheeling clutch 277 (not shown) may be positioned between the hub 122and target sprocket 202, as illustrated in FIG. 16(f), or positioned onthe motor pinion sprocket 242 as illustrated in FIG. 16(a).

Turning now to FIG. 16(e), the hub rotates around a bearing 126 mountedon the axle 118. The hub 122 is double ended and has extended ends 527having a sufficient annular extension 528 to form at least one andpreferably a pair of outward extended threaded assemblies 521. On oneend of the hub 122, the threaded assembly 521 receives the targetcoupler 202, which comprises the target sprocket 202 fixed to theannular coupler ring 529. This target coupler 203 has mating threads 523about the coupler ring 529, which allow the target coupler 203 to bescrewed to the threads 521 and thus to the hub 122 against a shoulder531 formed upon the hub 122. The plate 519 secures the bearing assembly206 and the mounting plate 204. The mounting plate 204, to which a motorand driving pinion sprocket is mounted as illustrated in FIG. 16(a), isthus secured to the target coupler 203 and hub 122 through the bearing206, which allows it to rotate with respect to the target coupler 203.Alternatively, a free wheeling clutch 277 (not shown) may be positionedbetween the hub 122 and target sprocket 202, as illustrated in FIG.16(f), or positioned on the motor pinion sprocket 242 as illustrated inFIG. 16(a).

FIG. 16(f) shows another embodiment with a free-wheel or one-way clutch277 mounted between the target sprocket 202 and the hub 122. The hub 122has a flange 551 and a threaded end 523 as in FIG. 16(e). The targetsprocket 202 can rotate in only one direction relative to the hub 122because it rotates on a free wheel clutch 277. This target sprocket202-clutch 277 assembly 280 is proximate to an assembly 282 comprisingthe mounting plate 204 and bearing 206 and it is separated from theassembly 282 such that each of the assemblies 280, 282 can rotateindependently around the hub 122. A retaining nut 553 secures theoverall assemblies 280, 282 to the hub 122 by the threaded end 523. Inthis embodiment, with the free-wheel clutch 277 mounted between thetarget coupler 203 and the hub 122, it is thus seen that the free-wheel277 can be located both in this location, as well as on the motor-shaftpinion gear, as described above.

Turning now to FIG. 17, a quick disconnect motor mount 500 which may beused with the present invention using either a chain, or belt drive asillustrated. For example, the “quick disconnect” feature for the motor230 will be used in several applications such as for folded bicycles, orin areas where security of the motor 230 may be required. The “quickdisconnect” feature can be used where the motor shaft 502 ends with aspline which slides in and out of the shaft on which a sprocket orsprockets is/are mounted. As illustrated, the motor shaft comprises anexternal spline 504, which engages a shaft 506 with an internal spline508 which is supported by two bearings 510,512 spaced apart on themounting frame 204. The motor housing includes quick release tabs 234,or the like, which may be quickly moved, thereby allowing the motorshaft 502 to be withdrawn or inserted within the shaft internal spline508.

Turning now to FIGS. 18(a), (b) and (c) a quick disconnect motor mount600 may be used with the present invention using a gear drive. Becauseof the gear to gear engagement between the pinion sprocket 242 and thetarget sprocket 202, merely rotating the tabs 234 as illustrated inFIGS. 18(a), (b) and (c) allows the motor to be removed from a unlockedto a locked position, respectively. As is apparent, by the mountingframe 204 including a shaft suitable to engage and disengage a motorshaft 244 from a power to a non-power posture upon either engagement orthe disengagement of the motor 230 from the mounting frame, the motor230 may quickly be removed for storage and safekeeping when necessary.

Merely by way of illustration, the following examples set forth typicaldesign parameters to achieve predetermined performance of torque andefficiency.

EXAMPLE 1

The present unitary power module can provide optimum bicycle performanceof torque and efficiency by reducing the RPM's of a high RPM motor to arelatively low number of revolutions per minute (“RPM”) suitable topower the bicycle at a predetermined speed. For example, for a givenpinion of modest diameter of 1″ (which is necessary to keep the unitarypower module reasonably small overall), the overall speed reduction ofthe motor RPM can be determined by the selection of the target sprocket.For a given target sprocket diameter of 7″ and the pinion diameter of1″, the resultant reduction ratio is 7:1. If a pinion gear is used, itmust be of this order of diameter to permit at least several teeth toengage the driven gear for low noise, efficiency and stress. At 10 milesper hour (“MPH”) for a 26″ wheel bicycle, the RPM, of the wheel and thedriven gear is 155 RPM. This would be for a motor of 1085 RPM.

EXAMPLE 2

Since most available motors run most efficiently at 3000 RPM or above, amuch higher reduction ratio is required. As illustrated in FIGS. 10(a)and 10(b), the desired ratio can easily be achieved with the 2-chainunitary power module and the planetary gear configuration previouslydescribed. In using an electric motor having an optimal rotationalcapacity of about 3000 R.P.M., a bicycle speed of about 12 MPH can beachieved as follows. By reference to the above FIGS. 10(a) and 10(b),S1=1″, S2=4″, S3=1″ and S4=4½″. Thus, a gear reduction ratio of about 18or 20 is accomplished and the above RPM speed to the bicycle wheel canbe achieved.

It is to be understood that variations on the embodiments of theinvention are possible. For example, the invention can be applied toeither the front wheel of the bicycle or the rear wheel, in a similarmanner as is described above by the application of the invention to therear wheel. This is readily achieved, as the power cable from thebattery appropriately placed is flexible and can readily adapted toreach and engage the motor.

In yet another variation, the mounting frame may have a hollow extensioncollar which can be attached by a bearing to the inside of the targetsprocket, such that the target sprocket freely rotates about the hollowextension collar.

In another variation, the present invention can be applied to numerousapplications where the advantages of implementing the invention can begained, such as mopeds, scooters, and motorcycles; three wheeledvehicles including tricycle-like vehicles; four wheeled vehiclesincluding wheel chairs, surrey style, golf cart style and delivery stylevehicles; multi-wheeled vehicles, material handling systems includingconveyor and pick-and-place style systems, and robotics.

In a further variation of the invention, the target wheel can beextended beyond a spoke wheel to any target wheel of any propulsionsystem. While the relative commonality of spoke weave pattern andconfiguration is important, it is not critical to implementing theinvention. For instance, in a solid “disk” wheel, the disk would havemounting holes, which would attach to the wheel in such a way tomaintain concentricity with the wheel.

In yet another variation, the invention can be applied to various drivesources including electric motors, gasoline engines, or any other typeof rotating drive source which would suitable for mounting to a mountingframe of the present invention.

In yet a further variation, the mounting frame may include a receivingcollar, spline or other suitable mechanical connection, which allows totarget coupler to be precisely aligned to the mounting frame. In thismanner, an opening in the mounting plate is not necessarily required.

The embodiments described above provide a number of significantadvantages. For example, because the propulsion system consists of themotor, pinion sprocket, clutch, target sprocket, and target wheel, thisinvention holds the entire propulsion system within the same referenceframe mandated by the mounting plate, thereby constraining thepropulsion system tolerances within the propulsion system. Thesetolerances are determined by the manufacturing tolerances of thepropulsion system components as designed independent of the vehiclemanufacturing tolerances. This allows the propulsion system to beapplied to any vehicle, while maintaining the performance of thepropulsion system.

This reference mounting frame is formed by the target sprocket or diskwith the hollow extension collar and grooved surface conforming a wheelpattern. This disk provides solid mounting attachment with the wheelthrough the grooved surface mating with the wheel hub and spokes. Thedisk is held concentric with the wheel hub. The sprocket gear isattached to the reference frame disk through either a free-wheelingclutch or directly attached to the reference frame disk. The motormounting frame is attached to the reference frame disk through a bearingon the hollow extension collar of the disk. The motor is attached to themotor mounting frame, in such a way as to provide for proper meshing ofthe pinion and driven (or sprocket) gears, independent of axle and hubbearing tolerances. The pinion sprocket is attached to the motor eitherdirectly, or through a one-way roller clutch, depending on whether thedriven (or sprocket) gear has a free-wheeling clutch. The motor mountingframe is clamped to the bicycle frame to prevent rotation of themounting frame. In this manner, the drive and target elements areproperly aligned to a single reference frame. This unitary or integratedfeature of the propulsion system being self-contained can bedemonstrated by holding the entire assembly by hand and running it. Itshould be noted that this invention avoids the axle assembly of thewheel, and as a result avoids the tolerance problems associated with theaxle and bearing. This is a significant, important aspect of thisinvention, and separates it from other drive systems.

Another important advantage of the invention includes the fact that thetolerances of the propulsion system are independent of the vehicle. Thepinion sprocket is held to the driven gear by the tolerances of thepropulsion system, rather than the tolerances of the axle or bearing ofbicycle frame. The axis of the pinion sprocket and motor are heldparallel with the wheel and target sprocket by the tolerances of thepropulsion system, specifically the mounting frame and reference targetsprocket. In the case of using gears, the meshing of the pinion sprocket(or pinion) and target sprocket gears are held to the tolerances of thepropulsion system. Thus, the reference frame disk provides the stableattachment of the propulsion assembly to the wheel.

Of course, it should be understood that a wide range of changes andmodifications can be made to the preferred embodiment described above.It is therefore intended that the foregoing detailed description beunderstood that it is the following claims, including all equivalents,which are intended to define the scope of this invention.

We claim:
 1. A unitary power module for a wheeled vehicle comprising: agenerally disk shaped target sprocket having a center opening to allowthe target sprocket to be placed about a wheel axle supported on a frameof a vehicle, the target sprocket connected to a target coupler that isconfigured to engage a wheel of a vehicle such that the target sprocketis substantially concentrically attached to the wheel by engagement ofthe wheel with the target coupler and without requiring replacement ofthe wheel; a power module mounting frame securable to a vehicle framethat is rotatably attached to the target sprocket to allow independent,aligned rotation of the target sprocket about the wheel axle, the powermodule mounting frame configured to receive an electric motor thatprovides power to a pinion sprocket affixed on the electric motor, thepinion sprocket configured to provide power to the target sprocket andcause rotation of the wheel of a vehicle, the power module mountingframe configured to provide a single point of reference for aligning apinion sprocket with the target sprocket; a free wheel clutch affixed toa shaft upon which said pinion gear is mounted and said pinion sprocketis positioned adjacent to and engages said free wheel clutch; and thetarget coupler is integral with the target sprocket and is disposed tobe affixed to a flange of a hub of a wheel.
 2. An unitary power modulekit for driving a two-wheeled vehicle having a frame and front and rearwheels, each wheel having a hub and wheel pattern with an axle,comprising: a member comprising a target sprocket and a mounting frame,the target sprocket comprising a disk shaped assembly having a centeropening to allow the target sprocket to be placed about a wheel axle,the target sprocket having a target coupler configured to engage one ofthe wheels of the two-wheeled vehicle to enable the target sprocket tobe substantially concentrically attached to a wheel of the two-wheeledvehicle by engagement with the wheel by securing elements and withoutrequiring replacement of the wheel; and the mounting frame is rotatablyattached to the target sprocket to allow for aligned independentrotation of the target sprocket on the mounting frame, the mountingframe having an element suitable to receive an electric motor to enablea pinion sprocket affixed on said electric motor to propel the targetsprocket and rotate the wheel engaged by the target sprocket, themounting frame providing a single point of reference for aligning thepinion sprocket with the target sprocket.
 3. The unitary power modulekit according to claim 2, where the two-wheeled vehicle is a bicycle. 4.The unitary power module kit according to claim 2, where the two-wheeledvehicle is a scooter.
 5. The unitary power module kit according to claim2, where the two-wheeled vehicle is a motor-scooter.
 6. A scootercomprising: a frame having at least one wheel with an axle and hubaffixed to a portion of the frame, the frame configured to receive abattery, a unitary power module comprising: a generally disk shapedtarget sprocket having a center opening to allow the target sprocket tobe placed about a wheel axle supported on a frame of a vehicle, thetarget sprocket connected to a target coupler that is configured toengage a wheel of a vehicle such that the target sprocket issubstantially concentrically attached to the wheel by engagement of thewheel with the target coupler and without requiring replacement of thewheel; and a power module mounting frame securable to a vehicle framethat is rotatably attached to the target sprocket to allow independentrotation of the target sprocket in relation to the power module mountingframe, the power module mounting frame configured to receive an electricmotor that provides power to a pinion sprocket affixed on the electricmotor, the pinion sprocket configured to provide power to the targetsprocket and cause rotation of the wheel of a vehicle, the power modulemounting frame configured to provide a single point of reference foraligning a pinion sprocket with the target sprocket.
 7. The scooteraccording to claim 6, further comprising: a battery attached to theframe; and an electric motor mounted on the power module mounting frame.8. A scooter comprising: a frame having at least one wheel with an axleand hub affixed to a portion of the frame, the frame configured toreceive a battery; a power module mounted on the frame, the power modulecomprising: a generally disk shaped target sprocket mounted on the wheeland indexed to the axle of the wheel so that rotation of the targetsprocket causes rotation of the wheel; a power module mounting frameindexed to the axle of the wheel separately from the target sprocket,the power module mounting frame rotatable independent of rotation of theaxle and the target sprocket; the power module mounting frame configuredto receive an electric motor that provides power to a pinion sprocketaffixed on the electric motor, the pinion sprocket configured to providepower to the target sprocket and cause rotation of the wheel of thescooter; an electric motor having a drive-shaft, said electric motorreleasably affixed to the mounting frame; and a pinion sprocketreleasably mounted on the electric motor drive-shaft.
 9. The scooteraccording to claim 8, wherein gears on the pinion sprocket engage gearson the target sprocket to provide power to the target sprocket.
 10. Thescooter according to claim 8, wherein a chain engages the pinionsprocket and the target sprocket to provide power to the targetsprocket.
 11. The scooter according to claim 8, wherein a belt engagesthe pinion sprocket and the target sprocket to provide power to thetarget sprocket.
 12. The scooter according to claim 8, wherein thepinion sprocket is releasably mounted on the electric motor drive shaftby a spline connection.